The couple condemned anyone attacking staff and said that it was "disgraceful that doctors have received death threats".

Charlie Gard with the toy monkey his father often carries to court with himCredit:
PA

Mr Gard accused Alasdair Seton-Marsden, who has previously delivered statements on their behalf, of fueling some of the backlash toward the hospital after he claimed that GOSH statement was a "cynical ploy".

The parents will return to the High Court today to try and persuade the judge to allow their 11-month-old son to travel to America for experimental treatment for his rare genetic condition.

Charlie's parents, who are in their 30s and come from Bedfont, west London, have already lost battles in the High Court, Court of Appeal and the Supreme Court in London.

They have also failed to persuade European Court of Human Rights judges to intervene.

But as they prepared for the last-ditch legal battle, Mr Gard and Miss Yates were caught up in a row over the actions of some people claiming to support their case.

Miss Yates said they are "extremely upset by the backlash" they have received since the hospital put out a statement on Saturday night as they only have Charlie's "best interests at heart". She added that they had been subjected to "hurtful comments".

Connie Yates and Chris Gard arriving at the Royal Courts of Justice Credit:
PA

She said: “Despite conflicting issues, we have always had the utmost respect for all the staff who work tirelessly at Great Ormond Street Hospital and the very difficult jobs they do every day.

“And, like them, we have been shocked by some of the public response to this case and agree with them that it is disgraceful that doctors have received death threats.”

Mr Gard used a social media post to distance himself from Mr Seton-Marsden, a former Ukip candidate, writing that he was not a spokesperson for the family and he had put out statements that they had not consented to.

"He is not helping us and he is certainly not helping Charlie", he said. "All he has done is tarnish the reputation of two parents who have been trying to save their son and we are getting a stream of abusive messages because of it."

He claimed that a GOSH allegation that other parents were "harassed" related to a time when Mr Seton-Marsden had asked other "distressed parents" to sign a petition and the family were unaware it was happening at the time.

Mr Gard added: "We have always acted in Charlie's best interests and we have never slated GOSH publicly, in fact we have been grateful to the staff for their care despite some conflicting issues.

"All the quotes you read in the media criticising GOSH, have come from him, not us."

A source close to Mr Seton-Marsden maintained that he had always been acting with knowledge of the parents and said that he had never attempted to get anyone to sign a petition in GOSH.

A rally in support of Charlie was yesterday held outside the Royal Courts of Justice by the American pro-life lobbyists who have flown to Britain to back the family.

Gregory Mertz, from organisation CitizenGO who organised the gathering, said they were hopeful that Charlie would be given residency in the US when the House of Representatives voted on the issue at the beginning of next week.